In the playback of digitally recorded audio, if done in conjunction with a visual display, such as a computer monitor, it is customary to provide some type of display that shows information regarding the audio amplitude and time offset (relative to the beginning or end of the recording) at the playback position. Typically, this takes the form of a rectilinear amplitude versus time waveform display. The reasons for providing the display can vary between the need for showing technical information regarding the audio and to provide an entertaining visual display (by viewing the audio waveform or frequency spectrum information, for example).
On the technical side, provision is usually made for manually altering the location of the playback position, such as using a cursor indicator on the display, controllable via input from a mouse. This is usually required for editing of the audio data, such as dividing a long recording into individual tracks. The editing is facilitated by observing visual cues in the display, such as regions of low signal amplitude, and using these regions as tentative locations for establishing track divisions. One drawback to this approach is that in the display of the overall waveform of a recording, the track separation locations cannot be resolved visually, because they are typically obscured by nearby audio having higher amplitudes. This is usually addressed by “zooming in” on a smaller portion of the waveform, permitting the visualization of the lower amplitude audio at track boundaries. However, since the zoomed waveform only comprises a subset of the entire audio recording, a tedious scrolling operation may be required to reliably find all track boundaries.
An additional drawback arises when editing audio not sourced from a quiet digital recording, such as when transcribing an actual analog vinyl record. Here, the amplitude at track boundaries doesn't drop to zero (digital silence); instead, a residual background noise (such as turntable low frequency noise, commonly known as “rumble”) is imposed on the quiet parts of the audio. Digital silence doesn't exist in analog transcriptions of vinyl records, so it's impossible to establish accurate track mark points (i.e., the start and end points or boundaries of the track) based only on the appearance of the waveform. For instance, a gradual song fade-out or fade in can be heard quite noticeably even in the presence of vinyl background noise, which may obscure the music, when viewed as the waveform.
Accordingly, there is a need in the art for a method and system for generating an intuitive and user-friendly visual representation of discretely sampled data, wherein a user may interact with the visual representation in the form of a conventional ‘vinyl’ record and record playback apparatus (i.e., a record player) to perform a number of tasks, including playback, editing, content management, and error/defect detection.